On the basis of the field outcrop survey and drilling data, in combination with laboratory thin section observation and trace element analysis, the authors employed such means as sedimentology and sedimentary geochemistry to conduct investigation. The results show that, in the Lower Permian Shanxi Formation of Xingxian area within Ordos basin, there exist 2 subfacies comprising deltaic plain and deltaic front and 7 microfacies composed of distributary channel, peat swamp, natural levee, splay, underwater distributary channel, interdistributary bay and channel mouth bar. The authors drew the sedimentary section of Shanxi Formation and compiled the sedimentary column of Shanxi Formation as well as Xiegou and Guanjiaya sections, which show that deltaic plain subfacies are mainly developed in Shan 1 Member whereas deltaic front subfacies are developed in Shan 2 Member of the study area. On the whole, during the deposition period of Shanxi Formation, the region showed a deposition process that the delta advanced southward gradually. The authors discussed the coal-accumulation process in the study area and pointed out that coals of Shanxi Formation were formed at the late stage of the short-term level ascending cycle. Coal-accumulation processes of 8^#, 7^#, 6^# coal seams occurred mainly in peat swamp that was developed in interdistributary bay of the deltaic front, whereas the deposition of 5^# coal seam occurred in peat swamp of the deltaic plain. The authors also analyzed the relationship between the thickness variation of coal seam and the sedimentary environment in the study area. It is evident that the distribution of thick coal zones of the Shan 2 Member coincides with the distribution of sandstone-rich belt, and that the coal seam thickness is in negative correlation with the percentage of gravel rock in Shan 1 Member of the study area.